Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Quando Jonny Leadbeater foi presidente?
 ###Tabelas: CREATE TABLE top_scorers_in_order_of_league_goals (top_scorers_in_order_of_league_goals_id AUTO_INCREMENT PRIMARY KEY, Player VARCHAR, Club VARCHAR, League INT, FA Cup INT, FA Trophy INT, League Cup INT, Total INT) CREATE TABLE locomotives_of_the_early_period_for_all_types_of_train (locomotives_of_the_early_period_for_all_types_of_train_id AUTO_INCREMENT PRIMARY KEY, Class VARCHAR, Number(s) VARCHAR, Quantity VARCHAR, Year(s) of Manufacture VARCHAR, Type VARCHAR) CREATE TABLE top_grossing_films_u.s. (top_grossing_films_u.s._id AUTO_INCREMENT PRIMARY KEY, Rank INT, Title VARCHAR, Studio VARCHAR, Director(s) VARCHAR, Gross VARCHAR) CREATE TABLE central_hawke's_bay_district (central_hawke's_bay_district_id AUTO_INCREMENT PRIMARY KEY, Name VARCHAR, Years VARCHAR, Gender VARCHAR, Area VARCHAR, Authority VARCHAR, Decile INT, Roll INT) CREATE TABLE executive_committee (executive_committee_id AUTO_INCREMENT PRIMARY KEY, Season VARCHAR, President VARCHAR, General Sec VARCHAR, Treasurer VARCHAR, Fixtures Sec VARCHAR, Social Sec Bradford VARCHAR, Social Sec Leeds VARCHAR, Media Officer VARCHAR)  
SELECT Season FROM executive_committee WHERE President = Jonny Leadbeater